ElectronicsQUICK REFERENCE
Power & Grounding
A reliable power layout for mixed logic, sensors and motors.
01Plan the rails
- Logic
- Use regulated rails appropriate to each board and sensor: commonly 3.3 V and 5 V.
- Motor power
- Use a supply and driver sized for startup/stall current. Keep motor current off MCU rails.
- Budget
- Add worst-case load currents and margin; check regulator temperature and battery capability.
02Ground & noise
- Reference
- Join MCU, sensor and driver grounds for non-isolated signal connections.
- Return paths
- Route motor return directly to the power distribution point; avoid sharing thin sensor return wires.
- Decoupling
- Use local ceramic bypass capacitors and suitable bulk capacitance near motor drivers.
03Before switching on
- Polarity
- Check connector polarity and voltage with a meter before attaching electronics.
- Protection
- Use appropriate fusing/current limiting and insulated connections.
- Multiple supplies
- Avoid back-feeding USB or tying regulator outputs together unless the board supports it.